Potassium Phosphate, Tribasic → 2-(4-Hydroxyphenyl)naphthalene-1,4-dione

HRID 884718Notes

Reaction equation

HRID 884718 reaction equation
Br[C:2]1[C:3](=[O:13])[C:4]2[C:9]([C:10](=[O:12])[CH:11]=1)=[CH:8][CH:7]=[CH:6][CH:5]=2.[OH:14][C:15]1[CH:20]=[CH:19][C:18](B(O)O)=[CH:17][CH:16]=1.P([O-])([O-])([O-])=O.[K+].[K+].[K+].C1(P(C2CCCCC2)C2CCCCC2)CCCCC1>C([O-])(=O)C.[Pd+2].C([O-])(=O)C.O.C1(C)C=CC=CC=1>[OH:14][C:15]1[CH:20]=[CH:19][C:18]([C:2]2[C:3](=[O:13])[C:4]3[C:9]([C:10](=[O:12])[CH:11]=2)=[CH:8][CH:7]=[CH:6][CH:5]=3)=[CH:17][CH:16]=1

Participants

8

Reactant 4

HCID 62657Potassium Phosphate, TribasicHCID 749441,4-Naphthalenedione, 2-bromo-HCID 75806TricyclohexylphosphineHCID 27343604-Hydroxyphenylboronic acid

Product 1

HCID 117768692-(4-Hydroxyphenyl)naphthalene-1,4-dioneYield 45.5%

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 962WaterSolvent2×HCID 1140TolueneSolvent

Conditions

Temperature
100 °C

Procedure

To a mixture of 2-bromo-1,4-naphthoquinone (1.0 g, 4.22 mmol), 4-hydroxyphenylboronic acid (640 mg, 4.64 mmol), potassium phosphate (3.135 g, 14.76 mmol), tricyclohexylphosphine (118 mg, 0.422 mmol), toluene (20 mL) and water (1 mL) was added palladium acetate (47 mg, 0.21 mmol) under N2. The reaction mixture was heated to 100° C. for 3 h. The reaction was cooled to rt and water was added. The mixture was extracted with EtOAc, and the combined organic extracts were washed with water and brine. The organic phase was separated, dried and concentrated to give crude product. Purification by column chromatography, using 10% EtOAc in hexane, gave 480 mg of 2-(4-hydroxy-phenyl)-[1,4]naphthoquinone (45%). MS (ES) m/z: 251.03 (M+1).

Workup

  1. temperatureThe reaction was cooled to rt
  2. extractionThe mixture was extracted with EtOAc
  3. washthe combined organic extracts were washed with water and brine
  4. customThe organic phase was separated
  5. customdried
  6. concentrationconcentrated
  7. customto give crude product
  8. customPurification by column chromatography

Sources & evidence

ORD record
ord-f3fd23c7f5a84b27899db9fc00c332a1
Source dataset
uspto-grants-2012_08
Patent number
US08242130B2

Reaction notes

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